Low-level clouds over tropical oceans play an important role in regulating climate and shaping its response to changes because they reflect much of the incoming solar radiation. We explore how the two types of such clouds - stratocumulus and trade-wind cumulus - are represented by the two novel global km-scale coupled climate models developed within NextGEMS project: IFS and ICON. These models differ in their strategy to represent subgrid-scale processes, in particular turbulent mixing. IFS employs complex parameterizations inherited from its NWP ancestor, including eddy-diffusivity mass-flux and convection schemes. ICON adopts a simpler approach and applies a minimal set of paramaterizations, including the Smagorinsky-Lilly closure. The seminar will present the analysis of cloud albedo, its variability with environmental parameters and the vertical structure of the atmospheric boundary layer in eight regions: four corresponding four corresponding to canonical Atlantic and Pacific stratocumulus and four in their downstream trades.